100 
Plate XVII 
Figure 1. AriacardiocercLs perrini Crickmay sp. nov., cross-sectional outlines of holotype, 
taken at 90 degrees behind the mouth border, A natural size. From external 
mould of holotype. (Page 58.) 
Figure 2. Anacardioceras perrini Crickmay sp. nov., holotype, lateral aspect, -h natural 
size. The reconstructed peripheral curve and mouth-border were obtained 
from part of the holotype not included in the photograph, namely an external 
mould of the full-grown shell. At 5 and 5i whorls the ribbing and venter 
are well shown. At 61 whorls a small fragment shows the ornament of the 
umbilical border. The entire specimen consists of 7i whorls. Locality No. 
24. Upper Jurassic. (Page 58.) 
Figure 3. Anacardioceras perrini Crickmay sj). nov., parat}™, X 5-2 cross-sectional 
outlines at 3f whorls. Protoconch is marked by a line of dashes which repre- 
sents the central axis of the shell. Shows elevation of whorl between 2f and 
3i whorls, and appearance of fastigate venter between 31 and 31. Locality 
No. 24. Upper Jurassic. (Page 58.) 
